Artificial leg



M. c. TARTE 3,546,712

ARTIFICIAL LEG 2 Sheets-Sheet l Dec. 15, 1970 Filed Juiy 9, '1 .968-

' `."v'VEN'I`U[ MAY c. 'TARTE BY 3 Z ATTORANEY &546.712

` Dec. 15, 1970 M c. TARTE ARTIFICIAL LEG Filed July 9, 1968 2 Sheets-Sheet 2 /42 INVENTOR.

mm c; 7795 775 HTTOR/ UEX United States Patent O 3,546,712 ARTIFICIAL LEG May C. Tarte, 1312 NE. Miami Court, Miami, Fla. 33132 Continuation-in-part of application Ser. No. 554,617, May 3, 1966. This application July 9, 1968, Ser. No. 748,132

Int. Cl. A61i" 1/04, 1/08 U.S. Cl. 3--24 10 Claims ABSTRACT OF THE DISCLOSURE An artificial leg having articulated joints including means alternately retainin-g the joints between a relatively locked condition and free articulated condition to permit a user to assume a substantially normal gait, in which said means includes a one-piece lock rod reciprocably supported in a lower leg-simulating portion and terminally extendin-g through the path of travel of relatively movable parts at the knee and angle joint, the lock rod being lockingly engageable at its upper end with a lock-socket and abuttingly engageable at its lower end with a displaceable socket in the foot portion of the artificial leg when a user's weight is applied thereon, and in which the rod is urged to an unlocked position when a users weight is removed permitted by automatic displacement of the displaceable socket away from the lower end of the rod.

This application is a continuation-in-part of applicant's copending application Ser. No. 554,617, filed May 3, 1966, now abandoned.

Generally speaking, fundamental prerequisites of artificial limbs is that they have a natural appearance, and have a movement which simulates natural movement. Further, the artificial limbs should be light in weight, simple in Construction, and readily maintained. An amputee using an artificial limb, be it leg or arm, for example, in addition to being extremely sensitive about the impairment, should receive all of the aid and comfort possibly available to aid him in overcoming the difiiculty.

Primary objects of the present invention are: to provide an artificial leg affording all of the prerequisites mentioned above; to provide an artificial leg which is relatively simple in Construction and operation, light in weight; to provide a substantially natural gait for the user in an automatic and unobtrusive manner; to provide improved lock-rod Operating mechanisms which insure an automatic simulated natural gait when taking a step, running, etc.

These together with more specific objects and advantages of the invention will become apparent from a consideration of the following description when taken in conjunction with the drawing forming a part thereof in which:

FIG. 1 is a side elevational view of an artificial leg and shown in section for purposes of clarity, illustrating the relative position of the parts when a users weight is imposed thereon;

FIG. 2 is a view similar to that of FIG. 1 showing the relative position of the parts when the user's weight is off the artificial leg, i.e. when taking a step;

FIG. 3 is a fragmentary, enlarged section taken substantially on the plane of line 3-3 of FIG. 1;

FIG. 4 is a view similar to FIG. 1 showing another embodiment of the novel artificial leg with the parts in the same general attitude as shown in FIG. 1; and

FIG. 5 is a View similar to that of FIG. 2 showing the parts of the artificial leg of FIG. 4 in the attitude assumed when weight is removed.

As is perhaps well known, it is quite common in the prior art for an artificial leg to include the three main elements, that of the lower leg, the upper socketed leg and &546312 Patented Dec. 15, 1970 the foot element, which elements are coupled together and arranged for movement relative to one another to simulate lifelike movement by an amputee. Numerous other V refinements may be included in amputees* prosthetic appliances such as knee cords, various types of straps and support devices such as belts or suspenders. The prior art as it has developed is set forth in U.S. Letters Patent 2,924,828 and this invention comprises an improved structure for the artificial body member of that Letters Patent with the invention residing principally in the provision of a simpler Construction, the utilization of which may be readly taught since amputees are not required to put their trust in springs which causes a fear in them of being thrown to the ground. The invention also includes an improved structure as is set forth more fully hereinater.

Referring now to FIG. 1, the upper leg element has been designated by the numeral 12, the lower element by the numeral 14, and the foot element by the numeral 16. In a suitable manner the upper and lower leg elements are pivotally connected by the pin means designated by the numeral 18 and, likewise, the foot element is connected to the distal end of the lower leg element by pivot means 20; any suitable means may be provided such as the clevis means indicated with suitable clearance being provided in the adjacent portions at the connection of the members. Interiorly of the lower leg element 14 a slender rod 22 is provided, the said rod being of a length such that it extends completely through the lower leg and at one end 24 into the upper leg and at the lower end 26 through the body of the foot element. The rod is slidably captivated in guide means 28 and 30 which permit of axial displacement only of the rod. As is clear in FIG. 1, the upper element 12 is provided with a socket member 31 which has a downwardly opening mouth with the lips thereof being fiared and gradually slo ing interiorly to a cylindrical-shaped well. Captivated in the well there is provided a spring-biased disk 32 which is normally urged outwaridly toward the mouth as seen in FIG. 2. The disk is provided with a recess in the floor which is companionately shaped to the rounded end 24 of the rod 22 for a purpose to be described. The lower end of the rod 26 is provided with a button 41 of lubric material and when the leg is in the locked position shown in FIG. l the rod is of a length such that the lower end 26 and the button 4-1 are in the plane of the bottom of the shoe element indicated as 'at 42, that is, extending through but not out of the hole 44 which, as seen in plan, is generally oval-shaped with the main axis being a forward to rearward axis as the foot element would be viewed in plan. The heel element 46 is pivotally connected to a transverse axis 48 in the foot element and includes stop` means 50* to limit movement of the heel element away from the plane of the bottom 42 of the foot element.

It is thus seen that the foot element is cou led to the distal end of the lower leg element while the lower leg element is distallv connected to the end of the upper leg element with both being pivotal with respect to a transverse axis as is the heel element. When the elements are in the position shown in FIG. 1, that is, when a wearer or amputee is standing, the rod 22 is received in the socket member into which it is urged as force is anplied to the heel element which causes the slidably captivated rod to move up into the socket and be guided thereinto by reason of the flared lip opening against the urging of the spring-biased floor. When the weight is taken off of the foot the heel element will, by a gravity action, pivot about the axis 48 until the stop at 50 engages the lower surface 42 of the foot element and in pivoting provides sufiicent clearance so that the rod 22 may slidably descend out of the socket and permit flexing of the upper leg element with respect to the lower leg element to the position shown in FIG. 2. The button 41 on the lower end 26 of the rod is of a replaceable nylon plastic material and includes a sleeve portion 56 to receive the end 26 of the rod and a distalmost dome-shaped portion 58 to facilitate in transmitting forces to axially displace the rod 22 with respect to the guide means. Also, the socket together with its spring-biased floor is replaceably sized for snug fitting in its recess within the joint cavity of the upper leg portion. Also, the rod 22, as indicated in FIG. 3, is of a Construction characterized by long, parallel spaced filamentatious material, all of the filaments being substantially aligned parallel to the longitudinal axis of the rod and bondcd together in a plastic binder body to define the rod-like structure. It has been found that this structure provides a uniformly resilient, strong and somewhat yieldable material simulating like-like response to the application of forces on the artificial leg. It will also be apparent that by reason of the lubric button connection for the purpose of transmitting forces to axially displace the rod 22 that the rod does not move forward and rearward in a shiftable pattern but may be confined to axial displacement only in the lower leg element.

Referring to the socket member 31, the spring-biased disk 32 included therein is included in the conventional unit available on the market and while not needed in order to initiate the sliding movement of the rod it is preferred for the reason that it tends to give the rod an initial force to speedily overcome inertia so that it slides to the position shown in FIG. 2 because of the pull of gravity. It is noted that by reason of the fact that the rod is limited by the guide means to movement of translation only which actually displaces the rod, there are no binding forces exerted upon it. Additionally, friction reducing elements indicated by the dotted lines in the guide means 28 and 30 may be provided; however, such are not required.

Referring to FIGS. 4 and 5, reference numerals similar to those used in FIGS. 1-3 will be used to describe similarly functioning parts; however, the hundreds digit 100 will be used.

Referring to FIG. 4, an upper leg element is indicated generally at 112, a lower element at 114, and a foot element at 116. These elements are pivotally articulated by suitable pivot means 118 and 120 as in the previously described embodiment.

A one-piece lock rod 122 includes an upper rounded terminal end 124, and lower end 126, and is reciprocably supported in suitable, co-aXial spaced guide sleeve means 128 and 130 which project into the lower leg. The lock rod extends through the path of relative movement between leg parts 112-116, as in the previously described embodiment. The upper leg part includes generally radiused downwardly-opening socket 129 permitting pivotal movement of leg part 114 as is illustrated in FIG. 5. Further, a downwardly-opening, flared, lock socket or abutment 131 removably accommodates the terminal end 124 of rod 122 when a users weight is imposed on the leg; see FIG. 4.

The socket 131 includes a complementary sleeve or liner 133 of any suitable friction-reducing material.

The lower end 126 of rod 122 preferably includes cap or button 141 produced from a suitable lubric or triction-reducing material such as Teflon or the like.

The lower foot element 116 includes a shoe 142 thereon, and the foot element 116 includes an enlarged through aperture 144 which opens to and communicates with a similar opening 145 formed in base or heel element 146. The floor 147 of opening 145 includes a liner 149 of a suitable lubric material, and thus accommodates for relative movement between cap 141 at the end of rod 122 and the foot element when articulation occurs between the foot element and lower leg element 114; as illustrated in FIG. 5.

The shoe 142 includes in circumposed relation about the rod 122 a compressible, spring means 151 ot any suit- 4 able character, which may be constructed as a synthetic or natural sponge or rubber element, which causes slight automatic downward movement of the foot element, heel portion, when a user takes a step (simulating normal movement of one's shoe heel in the absence of an artificial leg).

When weight of a user is imposed on the artificial leg; see FIG. 4, the spring means is compressed as seen at 151' in FIG. 4.

Fixed on an intermediate portion of rod 122, i.e. below sleeve or guide means 128 is an abutment Washer 123 which is retained against downward movement by a transverse pin 125. Interposed between the Washer 123 and the confronting portion of sleeve 128 is a compression spring 127 efiective to urge rod 122, i.e. end 124, downwardly and out of abutment socket 131, 133, the spring means 151 accommodating for such movement.

The spring 151, it will be noted in the exemplary embodiment, not only permits movement of rod 122, i.e. the locking end thereof out of its cooperating lock socket, but effectively seals the interior of the artificial leg, at its lower end, to obviate the entrance of foreign matter, moisture, etc. Although a coil spring 127 and compressible spring means 151 are disclosed and described, other similarly functioning equivalents are contemplated to be within the scope of the invention.

Briefly, when a user's weight is imposed on the artificial leg of FIG. 4, the leg is locked so that the user's weight is supported and a step can be taken off the foot 116 of this artificial leg. The spring means 151' will be compressed, as well as spring 127, and the lower end 126 of lock rod 122 will bear directly onto plate 147. The upper end 124 of rod 122 will lockingly en gage in socket 131, 133. Shifting of weight to the user`s other leg (not shown; be it natural or artificial) and raising of the leg shown, results in heel 146 being displaced downwardly, as shown in FIG. 5; rod 122 moving downwardly with the heel due to axial pressure caused by sprin g. 127. This movement, results in the heel moving down as in normal or natural gait of an individual, and release of end 124, permitting bend of the knee joint, i.e. at pivot 118. Simulated, natural movement will also occur at the pivot or articulated joint 120.

As a step is completed, and pressure is again applied through heel element 146, the rod end 124 is urged against the radiused socket 131 and when rod end 124 aligns with lock socket 131, 133, the articulated joints will be retained in the position shown in FIG. 4.

While the instant invention has been shown and described herein in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent apparatus and articles.

What is claimed is:

1. An artificial leg comprising, in combination, a simulated upper leg, lower leg and foot portions, articulated knee and ankle joint means between said upper and lower leg portions and said lower leg and foot portions, respec tively, the improvement comprising:

a substantially rigid one-piece, lock-rod extendin g the length of said lower leg portion and including free upper and lower terminal end portions projecting into said upper leg portion and foot portions, respectively, and beyond said knee and ankle joint means;

means reciprocably restraining said lock-rod to` longitudinal movement in said lower leg portion in spaced relation from said knee and ankle joint means;

said upper leg portion including a lower, downwardlyopening, concave recess substantially concentrc to said knee joint neans, said recess including a locksocket removably receiving the upper free terminal end of said lock-rod for locking said knee joint means;

said foot portion receiving said lower terminal end portion freely therethrough, and including a heel portion having a surface confronting the free, lower terminal end of said lock-rod and engageable therewith; and

means displaceably mounting said heel portion on said foot portion whereby a first position of said heel portion restrains said lock-rod in the lock socket of said upper leg portion, and serves to lock said knee and ankle joints, and a second position of said heel portion permits substantially free articulation of the knee and ankle joints.

2. The structure as claimed in claim 1 including spring means operatively connected to `said lock-rod and normally urging the upper end of said lock-red out of said lock-socket and normally urging said heel portion toward a position to permit free articulation.

3. The structure as claimed in claim 1 in which said lock socket includes a downwardly-diverging mouth for facilitating entry of the upper terminal end of said lockrod therein.

4. The structure as claimed in claim 1 in which said means displaceably mounting said heel portion comprising a hinge pin extending transversely through said foot portion in spaced relation from the lower terminal end of said lock-rod.

5. The structure as claimed in claim 1 in which said means displaceably mounting said heel portion comprises a resilient element interposed between said foot and heel portions.

6. The structure as claimed in claim 5 including sprinlg means operatively connected to said lock-rod and normally urging the upper end of said lock-rod out of said lock-socket and normally urging said heel portion toward a position to permit free articulation.

7. The structure as claimed in claim 5 in which said resilient element is circumposed intermediately about the lower end portion of said lock-rod for preventing foreign matter from Contacting said lock-rod.

8. The structure of claim 5 in which said heel portion includes an upwardly opening recess into which the lower terminal end of said lock-rod depends.

9. The structure as claimed in claim 7 in which the lower end of said lock-rod includes a cap of lubric material.

:10. The structure as claimed in claim 7 in which said heel portion includes a layer of lubric material engageable by the lower terminal end of said lock-rod.

References Cited UNITED STATES PATENTS 62,731 3/ 1867 Carleton et al. 3-24 2,512,826 6/1950 Clark 3-27X 2,605,474 8/1952 Oliver 3-1.2 2,619,652 12/1952 Vesper 3-l.2 2,870,453 1/1959 Vasquez 3-26 2,924,828 2/ 1960 Chiasson 3-27 FOREIGN PATENTS 736,030 8/1955 Great Britain 3-26 OTHER REFERENCES 1. Orthopaedic Appliances Atlas; Volume 2, Artificial Limbs, J. W. Edwards, Ann Arbor, Mich. 1960, page 193, Fig. 5.86.

LAWRENCE W. TRAPP, Primary Examiner RONALD L. FRINKS, Assistant Examiner U.S. Cl. X.R. 3-25, 27 

